Civilizations are organized in densely populated settlements divided into hierarchicalsocial classes with a ruling elite and subordinate urban and rural populations, which, by the engagement in intensive agriculture, mining, small-scale manufacture and trade. Civilization concentrates power, extending human control over the rest of nature, including over other human beings.[10]

The earliest emergence of civilizations is generally associated with the final stages of the Neolithic Revolution, culminating in the relatively rapid process of state formation, a political development associated with the appearance of a governing elite. This neolithic technology and lifestyle was established first in the Middle East (for example at Göbekli Tepe, from about 9,130 BCE), and Yangtze and later in the Yellow river basin in China (for example the Pengtoushan culture from 7,500 BCE), and later spread. But similar "revolutions" also began independently from 9,000 years ago in such places as the Norte Chico civilization in Peru[11] and Mesoamerica at the Balsas River. These were among the six civilizations worldwide that arose independently.[12] The neolithic revolution in turn was dependent upon the development of sedentarism, the domestication of grains and animals and the development lifestyles which allowed economies of scale and the accumulation of surplus production by certain social sectors. The transition from "complex chieftains" to "civilisations", while still disputed, seems to be associated with the development of state structures, in which power was further monopolised by an elite[13]

The word civilization comes from the 16th-century Frenchcivilisé (civilized), from Latin civilis (civil), related to civis (citizen) and civitas (city).[15] The fundamental treatise is Norbert Elias's The Civilizing Process (1939), which traces social mores from medieval courtly society to the Early Modern period.[16] In The Philosophy of Civilization (1923), Albert Schweitzer outlines two opinions: one purely material and the other material and ethical. He said that the world crisis was from humanity losing the ethical idea of civilization, "the sum total of all progress made by man in every sphere of action and from every point of view in so far as the progress helps towards the spiritual perfecting of individuals as the progress of all progress."[page needed]

Adjectives like civility developed in the mid-16th century. The abstract noun civilisation, meaning "civilized condition," came in the 1760s, again from French. The first known use in French is in 1757, by Victor Riqueti, marquis de Mirabeau, and the first use in English is attributed to Adam Ferguson, who in his 1767 Essay on the History of Civil Society wrote, "Not only the individual advances from infancy to manhood, but the species itself from rudeness to civilisation."[17]" The word was therefore opposed to barbarism or rudeness, in the active pursuit of progress characteristic of the Age of Enlightenment.

In the late 1700s and early 1800s, during the French revolution, civilization was said singular, never plural, and meant the progress of humanity as a whole. This is still the case in French.[18] The use of civilizations as a countable noun was in occasional use in the 19th century,[19] but has become much more common in the later 20th century, sometimes just meaning culture (itself in origin an uncountable noun, made countable in the context of ethnography).[20] Only in this generalized sense does it become possible to speak of a "medieval civilization," which in Elias's sense would have been an oxymoron.

Already in the 18th century, civilization was not always seen as an improvement. One historically important distinction between culture and civilization is from the writings of Rousseau, particularly his work about education, Emile. Here, civilization, being more rational and socially driven, is not fully in accord with human nature, and "human wholeness is achievable only through the recovery of or approximation to an original prediscursive or prerational natural unity" (see noble savage). From this, a new approach was developed, especially in Germany, first by Johann Gottfried Herder, and later by philosophers such as Kierkegaard and Nietzsche. This sees cultures as natural organisms, not defined by "conscious, rational, deliberative acts" but a kind of pre-rational "folk spirit." Civilization, in contrast, though more rational and more successful in material progress, is unnatural and leads to "vices of social life" such as guile, hypocrisy, envy, and avarice.[18] In World War II, Leo Strauss, having fled Germany, argued in New York that this opinion of civilization was behind Nazism and German militarism and nihilism.[21]

All civilizations have depended on agriculture for subsistence. Grain farms can result in accumulated storage and a surplus of food, particularly when people use intensive agricultural techniques such as artificial fertilisation, irrigation and crop rotation. It is possible but more difficult to accumulate horticultural production, and so civilisations based on horticultural gardening have been very rare.[23]Grain surpluses have been especially important because they can be stored for a long time. A surplus of food permits some people to do things besides produce food for a living: early civilizations included soldiers, artisans, priests and priestesses, and other people with specialized careers. A surplus of food results in a division of labor and a more diverse range of human activity, a defining trait of civilizations. However, in some places hunter-gatherers have had access to food surpluses, such as among some of the indigenous peoples of the Pacific Northwest and perhaps during the MesolithicNatufian culture. It is possible that food surpluses and relatively large scale social organization and division of labor predates plant and animal domestication.[24]

Civilizations have distinctly different settlement patterns from other societies. The word civilization is sometimes simply defined as "'living in cities'".[25] Non-farmers tend to gather in cities to work and to trade.

"No one in the history of civilization has shaped our understanding of science and natural philosophy more than the great Greek philosopher and scientist Aristotle (384–322 BCE), who exerted a profound and pervasive influence for more than two thousand years" —Gary B. Ferngren[26]

Compared with other societies, civilizations have a more complex political structure, namely the state.[27] State societies are more stratified[28] than other societies; there is a greater difference among the social classes. The ruling class, normally concentrated in the cities, has control over much of the surplus and exercises its will through the actions of a government or bureaucracy. Morton Fried, a conflict theorist, and Elman Service, an integration theorist, have classified human cultures based on political systems and social inequality. This system of classification contains four categories[29]

Economically, civilizations display more complex patterns of ownership and exchange than less organized societies. Living in one place allows people to accumulate more personal possessions than nomadic people. Some people also acquire landed property, or private ownership of the land. Because a percentage of people in civilizations do not grow their own food, they must trade their goods and services for food in a market system, or receive food through the levy of tribute, redistributive taxation, tariffs or tithes from the food producing segment of the population. Early human cultures functioned through a gift economy supplemented by limited barter systems. By the early Iron Age contemporary civilizations developed money as a medium of exchange for increasingly complex transactions. To oversimplify, in a village the potter makes a pot for the brewer and the brewer compensates the potter by giving him a certain amount of beer. In a city, the potter may need a new roof, the roofer may need new shoes, the cobbler may need new horseshoes, the blacksmith may need a new coat, and the tanner may need a new pot. These people may not be personally acquainted with one another and their needs may not occur all at the same time. A monetary system is a way of organizing these obligations to ensure that they are fulfilled. From the days of the earliest monetarised civilisations, monopolistic controls of monetary systems have benefited the social and political elites.

Writing, developed first by people in Sumer, is considered a hallmark of civilization and "appears to accompany the rise of complex administrative bureaucracies or the conquest state."[32] Traders and bureaucrats relied on writing to keep accurate records. Like money, writing was necessitated by the size of the population of a city and the complexity of its commerce among people who are not all personally acquainted with each other. However, writing is not always necessary for civilization. The Inca civilization of the Andes did not use writing at all but it uses a complex recording system consisting of cords and nodes instead: the "Quipus", and it still functioned as a society.

Aided by their division of labor and central government planning, civilizations have developed many other diverse cultural traits. These include organized religion, development in the arts, and countless new advances in science and technology.

Through history, successful civilizations have spread, taking over more and more territory, and assimilating more and more previously-uncivilized people. Nevertheless, some tribes or people remain uncivilized even to this day. These cultures are called by some "primitive," a term that is regarded by others as pejorative. "Primitive" implies in some way that a culture is "first" (Latin = primus), that it has not changed since the dawn of humanity, though this has been demonstrated not to be true. Specifically, as all of today's cultures are contemporaries, today's so-called primitive cultures are in no way antecedent to those we consider civilized. Anthropologists today use the term "non-literate" to describe these peoples.

Civilization has been spread by colonization, invasion, religious conversion, the extension of bureaucratic control and trade, and by introducing agriculture and writing to non-literate peoples. Some non-civilized people may willingly adapt to civilized behaviour. But civilization is also spread by the technical, material and social dominance that civilization engenders.

Assessments of what level of civilization a polity has reached are based on comparisons of the relative importance of agricultural as opposed to trade or manufacturing capacities, the territorial extensions of its power, the complexity of its division of labor, and the carrying capacity of its urban centres. Secondary elements include a developed transportation system, writing, standardized measurement, currency, contractual and tort-based legal systems, art, architecture, mathematics, scientific understanding, metallurgy, political structures, and organized religion.

Traditionally, polities that managed to achieve notable military, ideological and economic power defined themselves as "civilized" as opposed to other societies or human grouping which lay outside their sphere of influence, calling the latter barbarians, savages, and primitives, while in a modern-day context, "civilized people" have been contrasted with indigenous people or tribal societies.

"Civilization" can also refer to the culture of a complex society, not just the society itself. Every society, civilization or not, has a specific set of ideas and customs, and a certain set of manufactures and arts that make it unique. Civilizations tend to develop intricate cultures, including a state-based decision making apparatus, a literature, professional art, architecture, organized religion, and complex customs of education, coercion and control associated with maintaining the elite.

The intricate culture associated with civilization has a tendency to spread to and influence other cultures, sometimes assimilating them into the civilization (a classic example being Chinese civilization and its influence on nearby civilizations such as Korea, Japan and Vietnam). Many civilizations are actually large cultural spheres containing many nations and regions. The civilization in which someone lives is that person's broadest cultural identity.

Many historians have focused on these broad cultural spheres and have treated civilizations as discrete units. Early twentieth-century philosopher Oswald Spengler,[33] uses the German word "Kultur," "culture," for what many call a "civilization". Spengler believes a civilization's coherence is based on a single primary cultural symbol. Cultures experience cycles of birth, life, decline, and death, often supplanted by a potent new culture, formed around a compelling new cultural symbol. Spengler states civilization is the beginning of the decline of a culture as, "...the most external and artificial states of which a species of developed humanity is capable."[33]

This "unified culture" concept of civilization also influenced the theories of historian Arnold J. Toynbee in the mid-twentieth century. Toynbee explored civilization processes in his multi-volume A Study of History, which traced the rise and, in most cases, the decline of 21 civilizations and five "arrested civilizations." Civilizations generally declined and fell, according to Toynbee, because of the failure of a "creative minority", through moral or religious decline, to meet some important challenge, rather than mere economic or environmental causes.

Samuel P. Huntington defines civilization as "the highest cultural grouping of people and the broadest level of cultural identity people have short of that which distinguishes humans from other species." Huntington's theories about civilizations are discussed below.[34]

Another group of theorists, making use of systems theory, looks at a civilization as a complex system, i.e., a framework by which a group of objects can be analyzed that work in concert to produce some result. Civilizations can be seen as networks of cities that emerge from pre-urban cultures, and are defined by the economic, political, military, diplomatic, social, and cultural interactions among them. Any organization is a complex social system, and a civilization is a large organization. Systems theory helps guard against superficial but misleading analogies in the study and description of civilizations.

Systems theorists look at many types of relations between cities, including economic relations, cultural exchanges, and political/diplomatic/military relations. These spheres often occur on different scales. For example, trade networks were, until the nineteenth century, much larger than either cultural spheres or political spheres. Extensive trade routes, including the Silk Road through Central Asia and Indian Ocean sea routes linking the Roman Empire, Persian Empire, India, and China, were well established 2000 years ago, when these civilizations scarcely shared any political, diplomatic, military, or cultural relations. The first evidence of such long distance trade is in the ancient world. During the Uruk period Guillermo Algaze has argued that trade relations connected Egypt, Mesopotamia, Iran and Afghanistan.[35] Resin found later in the Royal Tombs of Ur it is suggested was traded northwards from Mozambique.

Many theorists argue that the entire world has already become integrated into a single "world system", a process known as globalization. Different civilizations and societies all over the globe are economically, politically, and even culturally interdependent in many ways. There is debate over when this integration began, and what sort of integration – cultural, technological, economic, political, or military-diplomatic – is the key indicator in determining the extent of a civilization. David Wilkinson has proposed that economic and military-diplomatic integration of the Mesopotamian and Egyptian civilizations resulted in the creation of what he calls the "Central Civilization" around 1500 BCE.[36] Central Civilization later expanded to include the entire Middle East and Europe, and then expanded to a global scale with European colonization, integrating the Americas, Australia, China and Japan by the nineteenth century. According to Wilkinson, civilizations can be culturally heterogeneous, like the Central Civilization, or homogeneous, like the Japanese civilization. What Huntington calls the "clash of civilizations" might be characterized by Wilkinson as a clash of cultural spheres within a single global civilization. Others point to the Crusades as the first step in globalization. The more conventional viewpoint is that networks of societies have expanded and shrunk since ancient times, and that the current globalized economy and culture is a product of recent European colonialism.

Historically civilizations were assumed by writers such as Aristotle to be the natural state of humanity, so no origin for the Greek polis was considered to be needed. The Sumerian King List for instance, sees the origin of their civilization as descending from heaven. However the great age of maritime discovery exposed the states of Western Europe to hunter-gatherer and simple horticultural cultures that were not civilized. To explain the differences observed, early theorists turned to racist theories of cultural superiority, theories of geographic determinism, or accidents of culture. After the second world war these theories were rejected on various grounds, and other explanations sought. Four schools have developed in the modern period.

The process of sedentarization is first thought to have occurred around 12,000 BCE in the Levant region of southwest Asia though other regions around the world soon followed. The emergence of civilization is generally associated with the Neolithic, or Agricultural Revolution, which occurred in various locations between 8,000 and 5,000 BCE, specifically in southwestern/southern Asia, northern/central Africa and Central America.[40] At first the Neolithic was associated with shifting subsistence cultivation, where continuous farming led to the depletion of soil fertility resulting in the requirement to cultivate fields further and further removed from the settlement, eventually compelling the settlement itself to move. In major semi-arid river valleys, annual flooding renewed soil fertility to be renewed yearly, with the result that population densities could rise significantly. This encouraged a "secondary products revolution" where domesticated animals became useful for more than meat production; being used also for milk, wool, and animal traction of ploughs and carts. The 8.2 Kiloyear Arid Event and the 5.9 KiloyearInterpluvial saw the drying out of semiarid regions and a major spread of deserts.[41] This climate change shifted the cost-benefit ratio of endemic violence between communities, which saw the abandonment of unwalled village communities and the appearance of walled cities, associated with the first civilisations. This "urban revolution" marked the beginning of stable agriculture and animal domestication which enabled economies and cities to develop. It was associated with the state monopoly and violence, the appearance of a soldier class and endemic warfare, rapid development of hierarchies and a fall in the status of women.[citation needed]

The Iron Age is the period generally occurring after the Bronze Age, marked by the prevalent use of iron. The early period of the age is characterized by the widespread use of iron or steel. The adoption of such material coincided with other changes in society, including differing agricultural practices, religious beliefs and artistic styles. The Iron Age as an archaeological term indicates the condition as to civilization and culture of a people using iron as the material for their cutting tools and weapons.[42] The Iron Age is the third principal period of the three-age system created by Christian Thomsen (1788–1865) for classifying ancient societies and prehistoric stages of progress.[43]

Karl Jaspers, the German historical philosopher, proposed that the ancient civilizations were affected greatly by an Axial Age in the period between 800 BCE–200 BCE during which a series of male sages, prophets, religious reformers and philosophers, from China, India, Iran, Israel and Greece, changed the direction of civilizations.[44]William Hardy McNeill proposed that this period of history was one in which culture contact between previously separate civilizations saw the "closure of the oecumene", and led to accelerated social change from China to the Mediterranean, associated with the spread of coinage, larger empires and new religions. This view has recently been championed by Christopher Chase-Dunn and other world systems theorists.

There have been many explanations put forward for the collapse of civilization. Some focus on historical examples, and others on general theory.

Ibn Khaldūn'sMuqaddimah influenced theories of the analysis, growth and decline of the Islamic civilization.[45] He suggested repeated invasions from nomadic peoples limited development and led to social collapse.

The decline of Rome was the natural and inevitable effect of immoderate greatness. Prosperity ripened the principle of decay; the cause of the destruction multiplied with the extent of conquest; and, as soon as time or accident had removed the artificial supports, the stupendous fabric yielded to the pressure of its own weight. The story of the ruin is simple and obvious; and instead of inquiring why the Roman Empire was destroyed, we should rather be surprised that it has subsisted for so long.[Gibbon, Decline and Fall of the Roman Empire, 2nd ed., vol. 4, ed. by J. B. Bury (London, 1909), pp. 173–174.-Chapter XXXVIII: Reign Of Clovis.--Part VI. General Observations On The Fall Of The Roman Empire In The West.]

Oswald Spengler, in his "Decline of the West" rejected Petrarch's chronological division, and suggested that there had been only eight "mature civilizations." Growing cultures, he argued, tend to develop into imperialistic civilizations which expand and ultimately collapse, with democratic forms of government ushering in plutocracy and ultimately imperialism.

Arnold J. Toynbee in his "A Study of History" suggested that there had been a much larger number of civilizations, including a small number of arrested civilizations, and that all civilizations tended to go through the cycle identified by Mommsen. The cause of the fall of a civilization occurred when a cultural elite became a parasitic elite, leading to the rise of internal and external proletariats.

Peter Turchin in his Historical Dynamics and Andrey Korotayevet al. in their Introduction to Social Macrodynamics, Secular Cycles, and Millennial Trends suggest a number of mathematical models describing collapse of agrarian civilizations. For example, the basic logic of Turchin's "fiscal-demographic" model can be outlined as follows: during the initial phase of a sociodemographic cycle we observe relatively high levels of per capita production and consumption, which leads not only to relatively high population growth rates, but also to relatively high rates of surplus production. As a result, during this phase the population can afford to pay taxes without great problems, the taxes are quite easily collectible, and the population growth is accompanied by the growth of state revenues. During the intermediate phase, the increasing overpopulation leads to the decrease of per capita production and consumption levels, it becomes more and more difficult to collect taxes, and state revenues stop growing, whereas the state expenditures grow due to the growth of the population controlled by the state. As a result, during this phase the state starts experiencing considerable fiscal problems. During the final pre-collapse phases the overpopulation leads to further decrease of per capita production, the surplus production further decreases, state revenues shrink, but the state needs more and more resources to control the growing (though with lower and lower rates) population. Eventually this leads to famines, epidemics, state breakdown, and demographic and civilization collapse (Peter Turchin. Historical Dynamics.Princeton University Press, 2003:121–127; Andrey Korotayev et al. Secular Cycles and Millennial Trends. Moscow: Russian Academy of Sciences, 2006).

Peter Heather argues in his book The Fall of the Roman Empire: a New History of Rome and the Barbarians[46] that this civilization did not end for moral or economic reasons, but because centuries of contact with barbarians across the frontier generated its own nemesis by making them a much more sophisticated and dangerous adversary. The fact that Rome needed to generate ever greater revenues to equip and re-equip armies that were for the first time repeatedly defeated in the field, led to the dismemberment of the Empire. Although this argument is specific to Rome, it can also be applied to the Asiatic Empire of the Egyptians, to the Han and Tang dynasties of China, to the Muslim Abbasid Caliphate, and others.

Bryan Ward-Perkins, in his book The Fall of Rome and the End of Civilization,[47] shows the real horrors associated with the collapse of a civilization for the people who suffer its effects, unlike many revisionist historians who downplay this. The collapse of complex society meant that even basic plumbing disappeared from the continent for 1,000 years. Similar Dark Age collapses are seen with the Late Bronze Age collapse in the Eastern Mediterranean, the collapse of the Maya, on Easter Island and elsewhere.

Arthur Demarest argues in Ancient Maya: The Rise and Fall of a Rainforest Civilization,[48] using a holistic perspective to the most recent evidence from archaeology, paleoecology, and epigraphy, that no one explanation is sufficient but that a series of erratic, complex events, including loss of soil fertility, drought and rising levels of internal and external violence led to the disintegration of the courts of Mayan kingdoms which began a spiral of decline and decay. He argues that the collapse of the Maya has lessons for civilization today.

Jeffrey A. McNeely has recently suggested that "A review of historical evidence shows that past civilizations have tended to over-exploit their forests, and that such abuse of important resources has been a significant factor in the decline of the over-exploiting society."[49]

Feliks Koneczny in his work "On the Plurality of Civilizations" calls his study the science on civilizations. Civilizations fall not because they must or there exist some cyclical or a "biological" life span. There still exist two ancient civilizations Brahmin-Hindu and Chinese which by no means are ready to fall any time soon. Koneczny claimed that civilizations cannot be mixed into hybrids, an inferior civilization when given equal rights within a highly developed civilization will overcome it. One of Koneczny's claims in his study on civilizations is that "a person cannot be civilized in two or more ways" without falling into what he calls an "abcivilized state" (as in abnormal). He also stated that when two or more civilizations exist next to one another and as long as they are vital, they will be in an existential combat imposing its own "method of organizing social life" upon the other.[50] Absorbing alien "method of organizing social life" that is civilization and giving it equal rights yields a process of decay and decomposition.

Political scientist Samuel Huntington[51] has argued that the defining characteristic of the 21st century will be a clash of civilizations. According to Huntington, conflicts between civilizations will supplant the conflicts between nation-states and ideologies that characterized the 19th and 20th centuries. These views have been strongly challenged by others like Edward Said, Muhammed Asadi and Amartya Sen.[52]Ronald Inglehart and Pippa Norris have argued that the "true clash of civilizations" between the Muslim world and the West is caused by the Muslim rejection of the West's more liberal sexual values, rather than a difference in political ideology, although they note that this lack of tolerance is likely to lead to an eventual rejection of (true) democracy.[53] In Identity and Violence Sen questions if people should be divided along the lines of a supposed 'civilization', defined by religion and culture only. He argues that this ignores the many others identities that make up people and leads to a focus on differences.

Some environmental scientists see the world entering a Planetary Phase of Civilization, characterized by a shift away from independent, disconnected nation-states to a world of increased global connectivity with worldwide institutions, environmental challenges, economic systems, and consciousness.[54][55] In an attempt to better understand what a Planetary Phase of Civilization might look like in the current context of declining natural resources and increasing consumption, the Global scenario group used scenario analysis to arrive at three archetypal futures: Barbarization, in which increasing conflicts result in either a fortress world or complete societal breakdown; Conventional Worlds, in which market forces or Policy reform slowly precipitate more sustainable practices; and a Great Transition, in which either the sum of fragmented Eco-Communalism movements add up to a sustainable world or globally coordinated efforts and initiatives result in a new sustainability paradigm.[56]

Cultural critic and author Derrick Jensen argues that modern civilization is directed towards the domination of the environment and humanity itself in an intrinsically harmful, unsustainable, and self-destructive fashion.[57] Defending his definition both linguistically and historically, he defines civilization as "a culture... that both leads to and emerges from the growth of cities," with "cities" defined as "people living more or less permanently in one place in densities high enough to require the routine importation of food and other necessities of life."[58] This need for civilizations to import ever more resources, he argues, stems from their over-exploitation and diminution of their own local resources. Therefore, civilizations inherently adopt imperialist and expansionist policies and, in order to maintain these, highly militarized, hierarchically structured, and coercion-based cultures and lifestyles.

The Kardashev scale classifies civilizations based on their level of technological advancement, specifically measured by the amount of energy a civilization is able to harness. The Kardashev scale makes provisions for civilizations far more technologically advanced than any currently known to exist (see also: Civilizations and the Future, Space civilization).

Examples of civilizations

The Acropolis, directly influencing architecture and engineering in Western, Islamic, and Eastern civilizations up to the present day, 2400 years after construction.

The Roman Forum, the political, economic, cultural, and religious center of the Ancient Rome civilization, during the Republic and later Empire, its ruins still visible today in modern-day Rome.

^It remains the most influential sociological study of the topic, spawning its own body of secondary literature. Notably, Hans Peter Duerr attacked it in a major work (3,500 pages in five volumes, published 1988–2002). Elias, at the time a nonagenarian, was still able to respond to the criticism the year before his death. In 2002, Duerr was himself criticized by Michael Hinz's Der Zivilisationsprozeß: Mythos oder Realität (2002), saying that his criticism amounted to a hateful defamation of Elias, through excessive standards of political correctness. Der Spiegel40/2002

^cited after Émile Benveniste, "Civilisation. Contribution à l'histoire du mot" (Civilisation. Contribution to the history of the word), 1954, published in Problèmes de linguistique générale, Editions Gallimard, 1966, pp.336–345 (translated by Mary Elizabeth Meek as Problems in general linguistics, 2 vols., 1971)

^ abVelkley, Richard (2002), "The Tension in the Beautiful: On Culture and Civilization in Rousseau and German Philosophy", Being after Rousseau: Philosophy and Culture in Question, The University of Chicago Press, pp. 11–30

^e.g. in the title A narrative of the loss of the Winterton East Indiaman wrecked on the coast of Madagascar in 1792; and of the sufferings connected with that event. To which is subjoined a short account of the natives of Madagascar, with suggestions as to their civilizations by J. Hatchard, L.B. Seeley and T. Hamilton, London, 1820.

^"Civilization" (1974), Encyclopædia Britannica 15th ed. Vol. II, Encyclopædia Britannica, Inc., 956. Retrieved 25 August 2007. Using the terms civilization and culture as equivalents is controversial[clarification needed] and generally rejected, so that for example some types of culture are not normally described as civilizations.

^"On German Nihilism" (1999, originally a 1941 lecture), Interpretation 26, no. 3 edited by David Janssens and Daniel Tanguay.

^Gordon Childe, V., What Happened in History (Penguin, 1942) and Man Makes Himself (Harmondsworth, 1951)